Process for condensing the acid fumes evolved during the concentration of sulphuric acid



PROCESS FOR CONDENSING THE ACID FUMES EVOLVED DURING THE INV'ENTORS.

Filed Dec. 13,

W. A. S. CALDER ET AL CONCENTRATION OF SULPHURIC ACID April 15, 1924.

Patented Apr. 15, 1924.

STATES 1,490,583 PATENT OFFICE.

WILLIAM ALEXANDER SKEEN CALDER AND WILLIAM HAROLD PALMER, OF BIR- MINGHAM, ENGLAND, ASSIGNOBS TO CHANGE AND HUNT, LIMITED, OF BIRMING- HAM, ENGLAND.

PROCESS FOR CONDENSING- THE ACID FUMES EVOLVED DURING THE CONCENTRATION OF SULPHURIG ACID.

Application filed December 13, 1922. Serial No. 606,697.

To all whom it may con-tent:

Be it known that we, lVlLLIAiI ALEXAN- DER SKEEN CALDER, a subject ofthe King of Great Britain, and residing at Ravensthorpe, Harborne, Birmingham, England, and \VILLiAM Huron) PALMER, a subject of the King of Great Britain, residing at 208 Londonderry Lane, Smethwick, Birmingham, England, have invented a new and useful Improved Process for Condensing the Acid Fumes Evolved During the Concentration of Sulphuric Acid, of which the following is a specification.

Various (lifiiculties are met with when condensing the acid fumes evolved during the concentration of sulphuric acid when the means employed consist in passing the gases carrying the fumes through a main or pipe or the like, having in it a constriction.

In the invention described in the British specification No. 126,320, of which one of us was a part-inventor, a process was described which consisted in causing gases containing such fumes to pass through a constriction in a main pipe or the like, while at atemperature above 95 .and below 135 C. at a minimum speed of 20 feet per second.

With a minimum speed of 20 feet per second obstructing means must be provided in the restricted zone for causing the gases to change their direction. otherwise the minimum speed of the gases should be 40 feet per second.

Good results are obtainable by this process and it is quite possible with a suitable velocity of the gases for the constricted portion of the pipe to be no more than eight inches long.

This invention relates to an improvement in this process.

We have now discovered that better and more regular results are obtained when the Water content of the gases under treatment is between 20 and by volume of water vapour.

The water is conveniently introduced in the form of steam or as a fine spray, or the gases may be caused to pass through water or through a tower or box packed with inert material over which water is caused to flow.

The accompanying drawings illustrate our invention.

Figure l is a cross section of a condensing arrangement, and Figure 2 a sectional elevation, while Figures 3 and 4 are similar views of a modification.

Referring to Figures 1 and 2, a is a main through which the gases to be treated flow,

while I) is a steam pipe by which the gases are given the content of water in accordance with this invention.

0 is a constriction in main a and d are tubes therein formed of glass or other suitable acid resisting material.

The cross section of constriction c and that of the tubes 03 and their length, vary according to circumstances but must be such that at the working speed of the fan employed, the velocity of the gases in the tubes 0? will be at least 40 feet per second.

In this construction the constricted zone is formed in two ways, viz. by the relatively small size of the portion 0 with respect to the main a and by tubes 03 in the main. The

tubes (Z, however, if of sufiic'ient length and sufficiently small (but not so small as to become blocked with acid) may alone constitute the. constriction.

Referring to Figures 3 and 4, a is a main, 6 a pipe for leading steam into main a, and are sets of bars formed of glass or other acid resisting material, one set of bars being staggered with regard to the adjacent set or sets of bars. a is a vessel into which the condensed acid passes.

The number of sets of bars must be such that at the working speed of the fan em ployed the velocity of the gases becomes at least 20 feet per second.

What we claim is 1. A process for condensing acid fumes evolved during the concentration of sulphuric acid, which consists in adding water to the gases conveying the acid fumes in such amount that the water content of such gases is after the addition of water between 20 and 35% by volume of water vapour, then causing such gases while at a temperature above 95 C. and below 135 C. to travel while in a constricted portion of a container at a speed adapted to condense the fumes.

2. A process for condensing acid fumes evolved during the concentration of sulphuric acid, which consists in injecting steam into the gases conveying the acid fumes in such amount that the Water content of such gases is afterthe addition of water between and by volume of water vapour, then causing such gases While at a temperature above C. and below C. to travel while in a constricted riion of a container at a speed adapte to condense the fumes.

3. A process for condensing acid fumes evolved during the concentration of sulpuric acid, which consists in adding Water to the gases conveying. the acid fumes in such amount that the water content of such gases is after the addition of water between 20 and 35% by volume of Water vapour, 16

In testimony that we claim the foregoing 20 as our invention We have, signed our names this 1st day of December, 1922.

WILLIAM ALEXANDER SKEEN CALDER. WILLIAM HAROLD PALMER. 

